Drive mechanism for a mechanical press

ABSTRACT

In a crank or eccentric press a main shaft is rotatably supported over a reciprocating ram or rams. Nonrotatably mounted on one end of the main shaft, a drive gear meshes directly with a drive pinion on a drive shaft which partly projects out of one side of the drive housing and which has a driving flywheel mounted on the projecting end. The other end of the main shaft is geared to a brake shaft having a portion projecting out of the other side of the drive housing and having a brake mounted thereon. Within the drive housing one or more axially spaced pairs of main pinions are fixedly mounted on the main shaft. Each pair of main pinions are in mesh with two pairs of main gears rotatable about fixed axes. Each main gear has a crankpin projecting therefrom and operatively coupled to the ram. This drive system makes possible the reduction of the height of the press.

BACKGROUND OF THE INVENTION

Our invention relates to a press, to a mechanical press, and inparticular to that of the crank or eccentric variety. Still moreparticularly the invention pertains to an improved drive mechanism forsuch a mechanical press.

In the conventional crank or eccentric press (shown in FIGS. 1 and 2 ofthe drawings attached hereto) which we believe is closest to that of ourinvention, a main shaft is rotatably supported within a crown or drivehousing supported above a slide or ram by uprights. The main shaft hasmounted thereon a pair of main pinions each meshing with a pair of maingears. A crankpin or eccentric cam projecting from each main gear iscoupled to the ram to cause same to move up and down in response to therotation of the main shaft. For revolving the main shaft the known presshas a drive shaft rotatably supported over the crown. The drive shafthas a driving flywheel, complete with a clutch, and a brake on itsopposite ends. The rotation of the drive shaft is transmitted to themain shaft via a drive pinion on the drive shaft, an idler gear, and adriven gear on the main shaft.

The above conventional drive system is subject to the drawback that,disposed over the press crown, the flywheel, clutch, brake, etc., addconsiderably to the height of the press. This drawback becomes all themore objectionable in the case of large, heavy-duty presses or thosehaving long slide strokes or slide adjustment strokes. For, if too high,a press may not be installed in a plant whose ceiling or roof is notsufficiently high. Even if there is some headroom above the installedpress, moreover, it may interfere with overhead cranes or the like. Theheight of presses should therefore be reduced as far as possible.

SUMMARY OF THE INVENTION

Our invention seeks to reduce to an absolute minimum the height of amechanical press of the class defined.

For the attainment of the above and other objects, our inventionprovides an improved drive mechanism for a mechanical press comprising amain shaft rotatably supported within a fixed drive housing over thepress ram or slide. On one end of the main shaft a drive gear is fixedlymounted and meshes with a drive pinion fixedly mounted on a drive shaftwhich is laid parallel to the main shaft. Also fixedly mounted on thedrive shaft is a flywheel, complete with a clutch, for impartingrotation to the main shaft via the intermeshing drive pinion and drivegear. The flywheel with the clutch is disposed on one side of the drivehousing. Disposed on the other side of the drive housing are brakingmeans acting on the other end of the main shaft. At least one pair ofmain pinions are fixedly mounted on the main shaft midway between itsends and are engaged with at least one pair of main gears rotatableabout a fixed axis within the drive housing. Also included are means fortranslating the rotation of the main gears into the up-and-down motionof the ram or slide.

Attention should be paid to the fact that, mounted on one end of themain shaft, the drive gear meshes directly with the drive pinion on thedrive shaft. This arrangement makes it possible to position the drivepinion, flywheel and clutch on one side of the drive housing, and thebraking means on the other side. Heretofore mounted on top of the crownor drive housing, these components of the drive mechanism can be placedbelow the top plane of the drive housing, with the consequent drasticreduction in the press height. Some of the components may projectupwardly of the drive housing as some press constructions demand, butonly to such an extent that the press height will nevertheless be farless than heretofore.

According to a further feature of our invention the braking meanscomprise a brake on a brake shaft which is coupled to the main shaft viatwo intermeshing gears. Thus the clutch and the brake are mounted onseparate shafts independently geared to the main shaft. This featuremakes it possible to adjustably vary the brake capacity by changing theratio of the gears connecting the brake shaft to the main shaft.

The above and other features and advantages of our invention and themanner of attaining them will become more apparent, and the inventionitself will best be understood, from a study of the followingdescription and appended claims, taken together with the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic representation of a prior art drive mechanismfor a crank or eccentric press bearing particular pertinency to ourinvention;

FIG. 2 is also a diagrammatic representation of the prior art pressdrive mechanism, as seen from the right hand side of FIG. 1;

FIG. 3 is a diagrammatic side elevation of the press drive mechanismembodying the principles of our invention;

FIG. 4 is a diagrammatic, developed sectional view, partly shown brokenaway for simplicity, of the press drive mechanism, taken along the lineIV--IV of FIG. 3, the drive mechanism being shown together with otherpertinent parts of the press which is herein shown as a crank press;

FIG. 5 is a view similar to FIG. 4 but showing a dual crank pressincorporating two drive mechanisms each constructed as in FIGS. 3 and 4;

FIG. 6 is a fragmentary side elevation, partly in section, of apractical form of the dual crank press constructed in accordance withthe teachings of FIG. 5; and

FIG. 7 is a developed sectional view of the dual crank press, takenalong the line VII--VII of FIG. 6.

DETAILED DESCRIPTION

The noted conventional drive system of a crank or eccentric press willbecome apparent upon consideration of FIGS. 1 and 2. It comprises a mainshaft 10 rotatably mounted within a crown 12. Fixedly mounted on theopposite ends of the main shaft 10, a pair of main pinions 14 mesh withtwo pairs of main gears 16. A crankpin or eccentric cam 18 projectingfrom each main gear 16 is operatively coupled to a ram or slide, notshown, to cause its up-and-down motion in response to the rotation ofthe main gears.

In order to cause the rotation of the main gears 16 the main shaft 10has a driven gear 20 fixedly mounted thereon intermediate its ends. Thedriven gear 20 meshes with an idler gear 22, which in turn meshes with adrive pinion 24 on a drive shaft 26 rotatably supported within an upwardextension 28 of the crown 12. The drive shaft 26 has its opposite endsprojecting out of the upward crown extension 28. Mounted on oneprojecting end of the drive shaft 26 is a flywheel 30 having a clutch32. A brake 34 is mounted on the other projecting end of the drive shaft26.

As has been stated, the mounting of the drive shaft 26, together withthe drive pinion 24, flywheel 30, clutch 32 and brake 34 thereon, on topof the crown 12 is objectionable by reason of the added height of thepress. Our invention succeeds in drastically reducing the height of thistype of mechanical press by providing an improved drive mechanism to beincorporated therein.

FIGS. 3 and 4 illustrate, in its simplest form, the crank pressincluding the improved drive mechanism of our invention. The pressincludes a ram or slide 40 movable up and down relative to a bed 42.Over the ram 40 a drive housing or crown 44 is immovably supported byuprights 46 for accommodating parts of the improved drive mechanismgenerally referenced 48. The drive mechanism 48 functions to impart thedesired up-and-down motion to the ram 40.

The drive mechanism 48 includes a main shaft 50 rotatably supportedwithin the drive housing 44. The opposite ends of this main shaftproject out of the drive housing 44 into its lateral extensions 52 and54. Fixedly mounted on one end of the main shaft 50, located in the lefthand drive housing extension 52 as seen in FIG. 4, is a drive gear 56which is in mesh with a drive pinion 58. This drive pinion is fixedlymounted on a drive shaft 60 rotatably supported in the drive housingextension 52 in parallel relation to the main shaft 50. Projecting outof the drive housing extension 52, one end of the drive shaft 60 hasfixedly mounted thereon a flywheel 62 having a clutch 64. The flywheelis belt driven by a motor or other prime mover, not shown, to causerotation of the main shaft 50 via the intermeshing drive gear 56 anddrive pinion 58.

Firmly mounted on the other end of the main shaft 50, projecting intothe right hand drive housing extension 54 as viewed in FIG. 4, is a gear68 meshing with a pinion 70 held fast on a brake shaft 72. This brakeshaft is rotatably supported in the drive housing extension 54 inparallel relation to the main shaft 50, with one of its ends projectingoutwardly therefrom. A brake 74 is provided to this projecting end ofthe brake shaft 72.

Within the drive housing 44 a pair of main pinions 76 are fixedlymounted on the main shaft 50 intermediate its ends. The main pinions 76mesh with one or more, two in the illustrated embodiment, pairs of maingears 78 rotatable about fixed axes 80. Each main gear 78 has a crankpin82 projecting eccentrically therefrom. The crankpins 82 on all the maingears 78 are operatively coupled, via links 84 and connecting rods 86,to the ram 40. The links 84 and connecting rods 86 function in the knownmanner to translate the rotation of the main gears 78 into theup-and-down motion of the ram 40.

Thus, since the drive gear 56 on one end of the main shaft 50 meshesdirectly with the drive pinion 58, the flywheel 62 and clutch 64 can bedisposed on one side of the drive housing 44, and the brake 74 on theother side of the drive housing. Consequently the press with theimproved drive mechanism 48 of our invention is considerably less inheight than the above described conventional press, as will beunderstood upon comparison of FIGS. 2 and 3 in particular.

We have diagrammatically illustrated in FIG. 5 a dual crank preess towhich the inventive concepts are also applicable. FIGS. 6 and 7 are moredetailed representations of the same dual crank press. As will be notedfrom all these drawings, the drive mechanism 148 incorporated in thedual crank press comprises two pairs of main pinions 176 mounted inspaced positions on a common main shaft 150 within a drive housing 144,for driving two rams 140 arranged side by side thereunder. The mainshaft 150 extends through, and is rotatably supported by, severalbearing walls 190, FIG. 7, within the drive housing 144.

On one end of the main shaft 150, projecting into the left hand drivehousing extension 152 as seen in FIGS. 5 and 7, a drive gear 156 ismounted for engagement with a drive pinion 158 on a drive shaft 160. Thedrive shaft has also mounted thereon a driving flywheel 162 having aclutch 164. The other end of the main shaft 150, projecting into theright hand drive housing extension 154, is coupled to a brake shaft 172via gears 168 and 170. The brake shaft 172 is provided with a brake 174.

Within the drive housing 144 each main pinion 176 meshes with two maingears 178 which are mounted on crankshafts 192 arranged about fixed axes180. Crankpins 182 projecting from the main gears 178 are operativelycoupled to the two rams 140 via links 184 and connecting rods 186.

The other details of construction and operation of this dual crankpress, and the advantages offered thereby, are substantially as setforth above in connection with the embodiment of FIGS. 3 and 4. It willbe seen that while we have shown and described the press drive mechanismof our invention as adapted for crank presses, our invention findsapplications in other types of mechanical presses.

We claim:
 1. A drive mechanism for imparting up-and-down motion to a ramin a mechanical press wherein the ram is moved up and down relative to abed, comprising:(a) a drive housing immovably supported over the ram;(b) a main shaft rotatably supported within said drive housing; (c) adrive gear fixedly mounted on one end of said main shaft; (d) a driveshaft rotatably supported in parallel relation to the main shaft; (e) adrive pinion fixedly mounted on said drive shaft and meshing directlywith said drive gear; (f) a flywheel having a clutch and fixedly mountedon said drive shaft for imparting rotation to said main shaft via theintermeshing drive pinion and drive gear, the flywheel and clutch beingdisposed on one side of said drive housing; (g) braking means disposedon the other side of said drive housing and acting on the other end ofsaid main shaft, said braking means comprising a brake shaft rotatablymounted to said drive housing in parallel relation to said main shaft,gear means connecting said main shaft to said brake shaft, and a brakeon said brake shaft; (h) at least one pair of main pinions fixedlymounted on said main shaft intermediate its ends; (i) at least one pairof main gears rotatable about a fixed axis within said drive housing andmeshing with said pair of main pinions; and (j) means for translatingthe rotation of said main gears into said up-and-down motion of saidram, said translating means comprising eccentric means on said maingears, and means for operatively connecting said eccentric means to saidram.